Pretax Impact on Assets and Liabilities as Result of Unlocking (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets:
Total assets (decrease) increase	$ (14,087)	$ (102,826)	$ (79,140)
Liabilities:
Total liabilities increase (decrease)	(40,262)	(221,635)	86,692
Net (decrease) increase	26,175	118,809	(165,832)
Deferred income tax (benefit) expense	9,161us-gaap_DeferredOtherTaxExpenseBenefit	41,583us-gaap_DeferredOtherTaxExpenseBenefit	(58,041)us-gaap_DeferredOtherTaxExpenseBenefit
Net (decrease) increase	17,014	77,226	(107,791)
Account balances and future policy benefit reserves
Liabilities:
Total liabilities increase (decrease)	(38,411)	(224,074)	86,596
Unearned premiums
Liabilities:
Total liabilities increase (decrease)	(1,851)	2,439	96
DAC
Assets:
Total assets (decrease) increase	(5,294)	(82,082)	(63,616)
DSI
Assets:
Total assets (decrease) increase	(8,673)	(20,860)	(14,512)
VOBA
Assets:
Total assets (decrease) increase	$ (120)	$ 116	$ (1,012)

Net (Decrease) Increase Due to Unlocking, Before Tax

No definition available.

Name:	ck0000072499_NetDecreaseIncreaseDueToUnlockingBeforeTax
Namespace Prefix:	ck0000072499_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Net (Decrease) Increase Due to Unlocking, Net Tax

+ References

No definition available.

+ Details

Name:	ck0000072499_NetDecreaseIncreaseDueToUnlockingNetTax
Namespace Prefix:	ck0000072499_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of other deferred income tax expense (benefit) pertaining to income (loss) from continuing operations. For example, but not limited to, acquisition-date income tax benefits or expenses recognized from changes in the acquirer's valuation allowance for its previously existing deferred tax assets resulting from a business combination and adjustments to beginning-of-year balance of a valuation allowance because of a change in circumstance causing a change in judgment about the realizability of the related deferred tax asset in future periods.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 6.I.7)

-URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section I

-Subsection 7

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Deferred Tax Expense (or Benefit)

-URI http://asc.fasb.org/extlink&oid=6510177

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (g),(h)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319

+ Details

Name:	us-gaap_DeferredOtherTaxExpenseBenefit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of expense due to change in present value assumptions used to value deposit assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 340

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6387650&loc=d3e9432-108338

+ Details

Name:	us-gaap_DepositAssetsEffectOfChangeInPresentValueAssumptionsRecordedAsExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of expense due to change in the present value assumptions on expected recoveries.

+ References

+ Details

Name:	us-gaap_DepositLiabilitiesEffectOfChangeInPresentValueAssumptionsRecordedAsExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_IncreaseDecreaseInInsuranceAssetsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_IncreaseDecreaseInInsuranceLiabilitiesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=ck0000072499_FuturePolicyBenefitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=us-gaap_UnearnedPremiumsLongDurationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnderlyingAssetClassAxis=ck0000072499_DeferredAcquisitionCostsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnderlyingAssetClassAxis=ck0000072499_DeferredSalesInducementsToContractHoldersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnderlyingAssetClassAxis=ck0000072499_ValueOfBusinessAcquiredMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: